Stop mechanism for knitting machines



X MarchY 1-,- 1938. M WACHSMAN 2,109,605

STOP MECHANISM FOR KNITTING MACHINES Filed May 19, 1937 INVENTOR.l

Patented Mar. l, 1938 PATENT OFFICE STOP MECHANISM FOR KNITTING MACHINES.

l. Michael waehsman, Brooklyn, N. Y. 4Application May 19, 1937, Serial No. 143,407

' '5 claims. 01. ca -163i This invention relates to improvements in stop mechanisms for knitting machines of the type shown in Reissue Patent 19,069, February 6, 1934. The stop mechanism'disclosed in `said patent ino cludes'el supporting box in which there is pivoted a knot detector leverand an end detector lever both of whichsupport the thread from the bobbinsQWhenga knot-occurs the knot detector lever ispulled down and makes an electrical con- !o tact inside the box .whereby tofclose an electrical circuit which inturn operates the stop mechanism of a knittingmachine. When the thread breaks 4or runs out, the end detector lever rises by gravity and likewise `serves. to close the electrical circuit.

l Inside the box arer electrical contact springs and thesaidtwo levers have contactheel which engage the said springs to close the circuit.- This ,i;ype lof. stop mechanism is wellknown in the art.

vHeretofore the contact springs have been in the gli formyof leafsprings which are not .easy to adjust and:which become readily bent out of shape by continuediuse. Furthermorebeing leaf springs wrancbloredat one end they cannot readily be adjustedtotsuch a fine degree as is required to space the'free'endsgfrom the `contact heels onthe detectorilevers. There is another disadvantage in that `the contactclosingmechanism is enclosed .iwithinlthe box and'itgisgtherefore not possible to checkany changeainwthe positions oi the con- 80 tactg'springs whichmay vbe caused by wear or by vibration or for other reasons.

The object of my'invention is to provide an improved contact mechanism to be used within the box of a device such as` described and disclosed in the said patent andother patents. Specificallyy the object-of myinvention is to employ spring actuated levers in place of contact springs and -to shape such levers Iso that they may be more easily,- and smoothly engaged by the contact heels. This .makes fora more positive and precise operation;A Other objects of my invention are to provide certain improvements which will be pointed out hereinafter and which serve chiefly the purpose of. more efiicient operation.

Accordingly. my invention is embodied in a stop mechanismfor knitting machines arranged [j and constructedas hereinafter set forth and as Iillustrated in the accompanying drawing in which Fig. 1 is a sectional view of the stop mechanism with parts removed and parts broken away.

Fig. 2 is a face view of the contacting levers which are engaged by the contact heels.

Fig. 3 is a horizontal detailed view showing the u arrangement of the knot detector lever and the end detector lever with relation to the box, parts being in section and parts broken away.

Fig. 4 is a sectional view showing a modied construction of the contact heel on the knot detector lever, parts being in section and parts 5 broken away.

Fig. 5 is a. plan view of the modiiied contact heel shown in Fig. 4.

Fig. 6 is a view partly in-section and with parts removed showing a modified construction of the l0 contact heel on the end detector lever.

In the drawing the contacting mechanism is contained within a suitably rformed box I having side walls 2 in which there is pivoted at 3 a gravity actuated end detector lever 4 which extend forl5v wardly from the box, Figs. 1 and 3, and which is caused to rise by means of a weight 5. At 6 there is pivoted a knot detector lever 1 which has two forwardly extending porcelain arms 8 one on each side of the end detector lever 4. The lever 1 is 20 held in its upper normal position against stops 9 formed in the front of the box by a spring I0 attached toa keeper II which moves between the side walls of the box and is adjustable by a screw I2 whereby to adjust the tension of the spring I0. 25

'I'his arrangement is disclosed in prior patents. It has been found, however, that because of vibration by the knitting machine the. keeper II does not remain in adjusted position upon the screw I2. I therefore propose to provide aV spring 30 I3 attached to the keeper and to the box. The spring exerts a steady pull on the keeper and prevents lcoseness between the keeper and the screw. Of course, when thekeeper is movedV up or down to adjust the spring I Il, the spring I3 will be 35 stretched accordingly as will be understood. The spring I0 is attached to the contact heel I4 of the knot detector lever. Similarly the end detector lever has a contact heel I5.

It is desirable that the contact making mecha- 40 v nism to be used in the box be so arranged that it may be assembled as a unit and thereafter attached without requiring any special tools or special eiort. In the present instance this mechanism is embodied in a contact plate I6 in which 45 there is pivoted at'I1 and I8 respectively an upper and a lower contact lever I9 and 20. The upper lever has a stop 23 and a contacting arm 2I which ends in a hook 22. The lower lever 20 is formed with a contacting arm or portion 2l and is 5o also provided with a stop 25. A spring 26 is attached to the two levers as shown and serves to keep them in contact making positions, the stops 23 and 25 engaging the contact plate for this purpose as shown and as will be understood.

'I'he contact plate with its levers is mounted in the box I before the cover 21 is attached and the attaching means may be a screw 28 and a bolt 29 which pass through the back of the box and whereby the plateis accurately positioned with respect to the two contact heels I4 and I5. The contact plate is suitably insulated from the box as indicated at 30. 'I'he bolt 29 serves as a .fixed circuit terminal in a manner well understood in the art, the circuit being indicated by the wire 2|.

'Ihe normal positions of the parts are as shown in Fig. 1. If a knot occurs on the thread 22, both levers will be pulled down. The contact heel I4 therefore rises and engages the contact portion 24 of the lever 20 with an easy wiping movement and thereby closes the circuit, the operation being well known in the art. When the thread breaks or runs out, the end detector lever will rise and its contact heel I 5 will engage the contacting arm 2| with an easy wiping movement. 'I'he rising movement of the lever 4 will be stopped by the hook 22. lever 4 reaches the dotted position at I3. The contact lever I9 therefore serves a two-fold purpose in that it closes the circuit by contacting the end detector lever and also stops the end detector lever in its upward swinging Jmovement so that it is not necessary to provide the end detector lever with a special bend or like means to insure that the lever does not swing too far.

Fig. 4 illustrates a modification in which the knot detector lever 1 is provided with a contact shoe I5 which, when the lever is pulled down by the thread, engages the contact arm 38 of the contact lever 41 pivoted at Il on the contact plate I6. In this instance the' contact lever is held in its upper predetermined position by a spring 39 which is coiled around the pivot 3l.

With a construction as inldg. 4 the knot de-v tector lever will likewise be kept in position by an individual coiled spring. 'I'his is not shown because it is a duplicate of the spring Il, the construction being the same.

It may not always be desirable to have an :outside-weight as l in Fig. 1. Il'ig. 6 therefore illustrates a modification in which the detector lever Hs provided with a counterweight 40 within the box. I'he counterweight is adapted to engage the upper contact lever I9 as will be understood. The weight is'fattachedl to the lever 4 by a set screw 4L which also serves to attach the upper end of a spring 42 the tension of which is adjustable by a screw 43. The construction in Fig. 6 includes the advantage of a very iine adjustment of the end detector lever by the spring 42.

I claimz- 1. In a stop mechanism of the character described, a housing, an upper and a lower thread supporting lever pivoted on said housing, each of said levers having a contact heel extending within the housing, a contact plate in the housing, an upper and a lower contact arm pivoted on the contact plate and adapted respectively to be This occurs when thev engaged by the contact heels of the said upper and lower thread supporting levers and means including a ilxed electric circuit terminal for supporting the contact plate in the housing to position the contact arms in operative relation to the said contact heels.

2. In a stop mechanism of the character described, a housing, an upper and a lower thread supporting lever pivoted on said housing, each of said levers having a contact heel extending within the housing, a contact plate, an upper and a lower contact arm pivoted on said plate, spring means secured to the contact arms for keeping the same in predetermined position with respect to said contact plate and to permit movement of said arms with respect to the plate, means for securing the latter within the housing with the said contact arms in relative predetermined operative positions with respect to the heels of the said thread supporting levers.

3. In a stop mechanism of the character described, a housing, an upper and a lower thread supporting lever pivoted on said housing, each of said levers having a contact heel extending within the housing, springs secured to said contact heels to maintain said levers in predetermined ilxed positions within the housing, a contact plate, an upper and a lower contact arm pivoted on said plate and adapted to swing with relation to the plate, a spring connecting said contact arms to maintain the latter in predetermined ilxed positions with relation to the plate and electric connecting means for connecting the contact plate to the housing.

4. In a stop mechanism of the character de scribed, a housing, an upper and a lower contact lever pivoted on the housing, each oi. said levers having a contact heel extending within the housing, acontact plate, an upper contact arm` pivoted on said plate, a stop on said contact arm adapted to be engaged by the upper contact heel, a lower contact arm pivoted on said plate and adapted to be engaged by the lower contact heel, spring means connected to said contact arms to maintain the same in predetermined yielding positions with respect to the said contact heels and means for securing the contact plate to the housing.

5. In a stop mechanism of the character described, a housing, an upper and a lower contact lever pivoted on the housing, each of said levers having a contact heel extending within the housing, a separate weight forming the contact heel on one of said levers, a contact plate, an upper contact arm pivoted on said plate, a stop on said contact arm adapted to be engaged by the upper contact heel, a lower contact arm pivoted on said plate and adapted to be engaged by the lower contact heel, spring means connected to said contact arms to maintainthe same in predetermined yielding positionsl with respect to thesaid contact heels and means for securing the contact plate to the housing.

MICHAEL WACHSMAN. 

